Hi there! I am currently experiencing the infamous "overheating DSP problem" with my freshly bought (2nd hand) Spider Valve HD100 mk1. I know a thing or two about computers, so I alreadly located the DSP chip, ordered some thermal adhesive tape, cut a PC heatsink to the appropriate size (20mm square) and now I need to connect a fan somewhere. I do have some nice and quiet 12V chip coolers that I can use. Can I connect those to the plug that powers the LED for the plexiglass frontpanel? I mean: I will remove it from the LED board and just connect it to the fan only. I'd like to keep it "backwards compatible" so I intend to solder a connector to the fan where I can plug in the connector that usually goes into the LED board. Also: I see there are 12V SMD 60cm LED strips available. Would it be possible to use such a strip on the OTHER LED panel so I can stick the ledstrip to the top of the casing and have it illuminate the whole thing just from one side (so I can use the other one for the fan)? Any thoughts? Thanx in advance!

For those interested in this matter: the frontpanel is lit by 5v LEDs instead of 12v.

I already stuck a heatsink to the DSP chip using Akasa thermal adhesive tape:

It holds the heatsink in place perfectly. The heatsink I am using comes from an old AMD Duron mainboard where this was on the chipset.

I am now working on connecting and placing the fan directly above the DSP chip. I am using a 12v PC chipset fan as these are pretty thin and fit in between the board and the casing. I intend to get the power from the 12v DC that powers the DSP board ( see above, just like nprenger did in this topic: http://line6.com/support/thread/91069 ) but as these are VH connectors I will try to stick the wires in the connector so I don't have to cut any wires. I think that will work with some aid of a tie wrap so it doesn't move (and I think a tie wrap is a better solution than tape if you keep in mind it will be getting warm in there).

You're on the right track. I like your solution better than mine because 1) the cooling will be concentrated at the chip where it's needed and 2) the fan will be inside, which should be less noisy assuming similar fan noise levels. My fan hasn't been loud enough to do anything about it yet, but I can hear it when I'm not playing. I'm interested to see how yours turns out. Keep us posted.

@ Nsprenger: I tried to contact you about this, but unfortunately the old forum isn't available any more for logging in, so sending a PM wasn't possible. Cool to see you here. ;-) Your info in that thread was most helpful, thanx! Did you experience the overheat problem ever again after applying your fan?

I found some Zalman cooling cable with a resistor that slows down the fan, which also has a positive effect on the noise. I intended to try to squeeze a bigger fan in (bigger fans usually make less noise) but unfortunately there isn't enough space.

After all I intend to do this operation only once... and a new fan only costs about 5 euros. Better do it good. ;-)

These fans are only 10mm high which should fit without any problem. I'm only still figuring out how to connect it to the chassis. I was thinking of car tape as that provides a very strong connection and it's a bit like foam, which should also reduce any vibrations and noise. Another option is silicone kit, which glues about anything. ;-) The clear version of this kit will be like rubber, which has the same advantage as foam. Also kit can hold pretty high temperatures.

Due to a strike of the national post delivery service I just got my fans today.

Here they are, two 40mm Blacknoise fans and one 25mm Papst fan. I just tested them and even though the Papst fan fits perfectly on top of the chipcooler, I think it makes too much noise (high pitched whining sound). It does blow pretty good though. The Blacknoise fans are just awesome. Really thin (10mm) so there won't be any trouble to fit them between the DSP board and the casing. I got two versions of this fan, the one on the right is the "noisier" one but it has a bigger throughput of air. I say "noisier", but in fact they are so quiet I expect I won't be hearing both of them once they are in place.

So I will go with the one on the right that pushes through the largest amount of air, after all I need it to cool the DSP chip.

I've never had an overheat with or without the fan. Usually, I keep the volume pretty low since I only play at home. I run my bias a little hot, though, and with the heat that the SVpre adds, I don't want to risk damaging the amp. With the mods I've made, I love my Mk I, so I want it to last a long, long time.

I've had my SV MK1 with SVPre for 5 years (I wrote quite a few messages on the old forums at the time of the release of the SVPre) and have never experienced the problem either, hence my question on another thread to know if anyone knows for sure if the problem arises on ALL SVMK1s or if it is completely random and only arose on some batches. True that I have mostly played it at home at a somewhat low volume, but I have gigged a few times with it and never had the problem.

So, am I just lucky or is it just a question of time before it happens ?

It's good to see you on here. I recognize your handle from the earlier forums.

I suspect that we will never know the answer to your question. If there were no component or manufacturing quality issues and if there were no design changes made to address overheating (we don't and probably won't know the answers to either of these questions because the L6 folks aren't obligated or probably even allowed to discuss warranty and reliability issues), it means that if there was an overheat on at least one unit, all of them are susceptible. That doesn't mean that all of them will acutally overheat, though. I have a feeling that whether it will happen or not depends on things like ambient temperature, natural air movement, bias setting, and how hard you're playing. All of these factors affect how much heat is generated or determine how effective the natural cooling is. The balance of heating and cooling determines the temperature of the sensitive parts and whether or not the amp has to shut down to protect itself. If you don't bias your amp super hot, stick it in a 95°F corner of the room, convert your combo to a closed back, and play with a heavy hand with the gain, channel volume, and master volume dimed, you'll be a lot less likely to overheat. I would imagine that there are thousands and thousands of satisified customers who have never overheated their amps or even know these support forums exist because they have never had a problem. All of this, of course, is just my opinion.

I'll just carry on using my amp as is and if I ever happen to experience the problem I'll just add a heatsink and if it doesn't cure the problem......I'll just get another amp or use it as a power amp only.

Another update. I didn't want to cut the 12V cable so I soldered a new one. I got some 3 pin connectors (raster 3,96mm VH series).

These are normally connected by crimbing but the tool needed for that is really expensive, so I soldered them. I put 2 extra wires with a 3rd connector on one end so I can use that to connect the fan and also make it easy to disconnect it when needed. The wires are taken from an old PC power supply.

For those interested: it's easy to open up the connectors. Just take a really small screwdriver or pen and press down on the metal strip in the connector, at the end closest to the wires. Then genty pull the cable and you'll get the pin out.

I had hoped this was the final step but I noticed my fan is a bit too noisy so I intend to slow it down a bit using a resistor or a voltage regulator. So I guess I'll be soldering some more this weekend. ;-)

I soldered everything and fixed the fan problem. It seemed I connected it to +12V and -12V instead of +12V and GND. That also explains the noise, it was running on double speed. Now that's corrected it's "weally weally qwuiet".

So I also put the fan in place. It's glued in using high temperature resisting silicone kit (it should be resistant to about 300 degrees C so that should be enough). As silicone kit is flexible, it will also reduce any vibrations from the fan (if there were any). As you might be able to see, I screwed in some spacers from a PC mainboard (you know, those pins that allow you to screw your mainboard to the PC chassis) to get a little bit of space between the chassis and the fan, so it can suck in some air.

Hm... it didn't really go as planned. It seems the power transformer is not strong enough to power both the fan and the DSP board.

@ Nprenger : I guess you were lucky with a stronger power transformer or your fan hardly uses any power... In my case I fried 2 diodes on the board. They are replaced now and it all works again, but without the fan. Luckely I know someone who is an absolute guru with tube amps, so he is currently fixing me a small extra transformer that will coexist with the original one, so it can power the fan without interfering.

Oh man, sorry to hear that. You're right - either way I'm lucky. Either I'm lucky because I have a good transformer or because I happened to use a low-power fan without giving it a second thought. I haven't had any problems yet. I played mine in the basement about as loud as I could stand it for a few hours a few weeks ago and it seemed fine.

S**t happens. If you're messing with fire, you can expect to burn your fingers once in a while.

Here's the fried diode:

As you can see above, the first one is cracked. The last one (at the bottom) was short circuiting, so to be sure the tube guru replaced all 4 and everything was working again.

Just picked up the amp today, it's all working incl. the fan and a ledstrip (the red/black wire goes to the fan, the other one to the leds).

My friend the tube expert has added some power regulator to the tube socket which increases the current so now I got a steady source of power. This goes beyond my knowledge of electronics but if anyone is interested: he draw me a small schematic, I can put that online as well.

But first: the big test! Next Tuesday we'll be rehearsing for 3 hours so if all goes well, I am in the clear.

LED strip into place. It's an adhesive 12V SMD LED strip which I put on the frontpanel, out of sight - just above the screws. From the back it looks like that famous district in the capital of my country. However, from the front you don't see the LEDs but the tubes and other components light up red, it's actually pretty subtle. Today I will spraypaint the inside of the backpanel (mesh) with silvercolored paint so it will reflect the red light a bit more.

Just a last update: it´s been 2 months now and we did a couple of gigs in the meantime as well as a weekly 3 hour rehearsal session (which are quite loud).

I haven´t experienced any problems ever since, so I think I can recommend this fix to anyone having the same problem. I think all the info you need is in this topic but ofcourse you can always send me a PM if you have any specific questions.

My cousin entrusted me with repairing/modyfying his amp to a usable state. He has the Line6 Spider Valve 112 and was told by other technicians that the DSP chip need replacement but wouldn't want to take the risk themselves since they are scared that the heat used in removing the chip will damage the components near it.

I have not powered up the amp yet since I don't have a guitar to test it with and I'm not sure what can be used as a valid test signal.

The DSP board has the same text written underneath the ribon cable connector ( A15: SV MAIN #35-00-0250 REV A 8June2007) I'm still waiting for my cousin to get back to me as to what he experienced was wrong with it.

I also noticed that the two resistors R58 and R59 looks 'burnt' they are covered under glue but there is yellowish marks and the value markings of the resistors aren't that readable anymore

Is there maybe an indepth manual to the electronics? (long shot, I admit)

I also noticed some "burnt" stuff on the board (especially on the back) but closer inspection revealed it was only burned glue; the actual resistors were fine. So I guess it just got a bit too hot. Also: the re are some aluminium "spacers" that have a dual function: besides keeping the DSP board of the casing, they are also heatsinks. They are connected to the LM1086 regulators on the DSP board (and those can get pretty hot). You can see them on the first picture in this thread. The burnt glue/silicon/whatever was on the back of these.

If you can post an image of the R58 / R59 maybe someone else can help you out? If the markings on their resistors are still visible you should be able to find out what you (might) need.

The heatsink works really good btw. so if overheating is the problem I'd recommend to try that first as the DSP board is pretty expensive. ;-)

Very interesting stuff. I have just had a Mk II fixed up to deal with the overheating DSP issue, and I wonder if it's going to come back due to the tubes running hot. Would like to know if your fan modification is still running without issues.

Very interesting stuff. I have just had a Mk II fixed up to deal with the overheating DSP issue, and I wonder if it's going to come back due to the tubes running hot. Would like to know if your fan modification is still running without issues.
My post is herehttp://line6.com/sup...heating-in-amp/
Thanks,
Brian

I've been running a cooling fan from the DSP's voltage source for around 2 years with no problems. I typically use this amp a few times a week.